In U.S. Pat. Nos. 3,706,439 and 3,817,610 there are disclosed viewers which utilize separate cartridges. The same is true in copending application Ser. No. 535,376, filed Dec. 23, 1974. In all of these embodiments there is a need for a viewer and separate cartridges which can be removably inserted therein. In certain applications, it has been found that there is a need for a simplified arrangement which does not require the use of separate viewers and separate cartridges. There is, therefore, a need for a new and improved cartridge viewer which eliminates such difficulties.